Sand-blast machine.



F. P. BOLAND.

SAND BLAST MACHINE.

APPLICATION FILED NOV. 27, 1'908.

Patented 'Mar. 9, 1909.

//\/ VEN TCJR W/ TNEEEEE and communicating FRANCIS P. BOLAND, QFPROVIDENCE, RHODE ISLAND.

Specification of Letters Patent.

I SAND-BLAST MACHINE.

Patented'March 9, 1909.

Application filed November 27, 1908. Serial No. 464,729.

means and also in the construction of the mixing head or chamber, fromwhich latter the abrading material is discharged via the outlet-nozzle,all as more fully hereinafter set forth and claimed.

In the. accompanying sheet of drawings, Figure 1 re resents a verticalsectional view, in partial e evation, of a sand-blast machine embodyingmy improvements. Fig. 2 is a vertical central section of the mixing headand its connections, in enlarged scale. Fig. 3 is a horizontal sectionalview taken on line 3' 3 of Fig. 2. Fig. 4 is a vertical centralsectional view, also in enlarged scale, showing the construction of thesand and air feeding device adapted to be located at the bottom of thesand reservoir, and Fig. 5 is a horizontal section, taken on line 5 5 ofFig. 4.

In my im roved sand-blast machine I employ a suita ly supportedpreferably square or rectangular casing 0 having glass sides, inclosingthe working chamber a, a beveled top a and a sand reservoir e, thelatter being located immediately below the chamber a therewith via theperforated plate '5. An extension f terminating in the exhaust flue 9leads from the rear of the chamber a. The front side of the casing isprovided witha swinging door 0 and a guard or protector w arranged withrespect to the usual hand-holes d and located below said door. 'I makeno claim to the ele-' merits before described.

An air-blast ipe h adapted to be connected with a suita le source ofairsupply passes centrally downward through the top of the machine andterminates in the mixing head A," soon to be described. A branch .pipe mextends rearwardlyend downwardly fromthe pipe h and is secured-in thetop' of thehollow casting B, in turn adapted to rest on and be supportedby the bottom wall of said reservoir 'e. the respective pfiipes h and mare e'rnp contro ing the "Cocks k and m inter osed 4 oyedfor. ow of air.The sald'casting' ftion o the discharge-nozzle k relation to the plateB, shown more clearly in' Fig. 4, practically for IS a chamberedreturn-bend, the air from the inlet-pipe m in this case flows clirectlytherefrom through an open short upright nozzle 1) tapped into thetopofthe cast-" ing. The lower end of what maybe termed the main circulat'-pipe a freely surrounds the nozzle 6 and is 25s ber B. One side of pipeu is provided with an opening t6 near the bottom extending to or nearlyto the top of the nozzle, the upper portion of the latter being cut awayat b on the side opposed to constructed the casting and the lower porotapped into the memsaid opening u. As thus tion of pipes m and dare whenin service completely surrounded by the sand or abrading materialcontained in the reservoir 6; the arrangement being such that the sandflows by gravity through opening a and fills the annular space 8 lyingbetween the members a and I), while at the same time the ressure of theair issuing from the nozzle ii drives the sand from the space 8 andforces itupwardly in the circulating-pipe to be further mingled with airin the mixing-head A and finally discharged'from the latter onto theWork. The said member A comprises a casting provided with an enlargedcham bered cylindrical u per portion 0 having converging side wa sterminating at the bottom in a central nozzle 0 and having an upwardlyinclined branch or nozzle n arranged tangentially to and being incontinuous open communication with said chamber 0. The lower portion aof the member 'n, is secured tothe upper end of the circulating-pipe u.The inner Walls of the chamber 0 may be provided with suitably disposedintegral lugs or buttonlike projections p;

these latter as well as the inwardly extending lug 0 located contiguousto one side of the outlet end of the tubular branch at are employed tobreak up the rotative or swirling action of the sand discharged into thechamber and cause it to fall in a more uniform or even manner so as tobe acted'upon more efficiently by the air discharged from the mouth ofpipe h at the annular point 0 Fig. 2. The thus acted upon sand passes,via tube 70, into 'said nozzle 0 and the telescoping tube is to thesuitably shaped outlet nozzle k and is discharged therefrom onto thework supported beneath. A screw k may beem loyed for readily changingthe posivertically I I am aware that it is a well-known practice toProvide sand-blast machines withmeans for continuously circulatin andre-using the sand. and therefore I disclaim such feature broadly, exceptas to the novel construction and arrangement of devices employed as setforth in the following claims.

I claim as my invention and desire to secure by United States LettersPatent 1.- Ina sand-blast machine, rovided with a'working chamber and asan reservoir lo-.

' cated therebelow, the combination therewith of a chambered member orcasting B supported in the reservoir so as to be embedded in the.sand,'-a pipe for admitting air under pressure into the casting, ashort outlet-nozzle secured to and extending upwardly from the latter,said inlet and outlet members being in continuous open communicationwith I the chamber of said casting, a circulatingipe also secured to thecasting having its ower portion' perforated and inclosing said nozzleand forming. an annular space therebe-.

tween into which space'sand may flow by ravity but not' into theca'stings chamber, a hollow head; member located in the said workingchamber connected to and being in 1 continuousopen communication withthe circulating-pipe foriintroducing l sand into the head, a nozzleconnected wit the lower portion of said head, and means for forcing thethusintroduced sand downwardlyfrom the i head and discharging it throughthe nozzle,

substantially as herelnbefore described;

1 2. In a machine of the character described,

the combination of a chambered casting memberB constituting areturn-bend, an et pipe m tapped into the'said member, a main circulatin-pipe it having its lower end tapped into t e member B but not extending.into its chamberhavin a lateral opening'through its wall, a sma lerpipe 6 forming anair-outlet nozzle tapped into the casting fordischarging, air therefrom, and having said nozzle arrangedconcentrically with and inclosed by the circulatin -pipe so as to form aspace between them, ti

upper edge of said lateral opening.

3. In a machine of the character described, the combination of a headmember havin a 'mixin -chamber proper therein provi ed with ownwar'dly.converging side walls tere u per end of the nozzle extending to or beyontheminating at its lower end in a dischargeoutlet having a materiallyreduced cross sectional area, a pipe extending downwardly through the,head 1nto the chamber for admitting air under pressurefa branch nozzleopening into the mlgrlng-cliarnber, said nozzle being non-central orofiset-with relation to the atter and also extending downward at anangle therefrom, and a circulating-pipe connectedto the lower or freeend of said 4 branch nozzle for conducting sand and air from a source-ofsupplyinto the mixingchamber.

and a series'of short projections formed onthe inner'wall of thechamber'ior the purpose herein set-forth.

Signed t Prov'idence, R.. 1., this 24th day of November, 1908..

Witnesses:

OALvIN H. BROWN, GEO. H. REMINGTON.

FRANOISlfz'BOLAND.

